/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 1999-2002 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
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 * 4. The names "Xerces" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
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 * 5. Products derived from this software may not be called "Apache",
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 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation and was
 * originally based on software copyright (c) 1999, International
 * Business Machines, Inc., http://www.apache.org.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

package com.sun.org.apache.xerces.internal.impl.dtd.models;

import com.sun.org.apache.xerces.internal.xni.QName;

import com.sun.org.apache.xerces.internal.impl.dtd.XMLContentSpec;

/**
 * MixedContentModel is a derivative of the abstract content model base
 * class that handles the special case of mixed model elements. If an element
 * is mixed model, it has PCDATA as its first possible content, followed
 * by an alternation of the possible children. The children cannot have any
 * numeration or order, so it must look like this:
 * <pre>
 *   &lt;!ELEMENT Foo ((#PCDATA|a|b|c|)*)&gt;
 * </pre>
 * So, all we have to do is to keep an array of the possible children and
 * validate by just looking up each child being validated by looking it up
 * in the list.
 *
 * @xerces.internal
 */
public class MixedContentModel
    implements ContentModelValidator {

  //
  // Data
  //

  /**
   * The count of possible children that we have to deal with.
   */
  private int fCount;

  /**
   * The list of possible children that we have to accept.
   */
  private QName fChildren[];

  /**
   * The type of the children to support ANY.
   */
  private int fChildrenType[];

    /* this is the EquivClassComparator object */
  //private EquivClassComparator comparator = null;

  /**
   * True if mixed content model is ordered. DTD mixed content models
   * are <em>always</em> unordered.
   */
  private boolean fOrdered;

  //
  // Constructors
  //

  /**
   * Constructs a mixed content model.
   *
   * @param children The list of allowed children.
   * @param type The list of the types of the children.
   * @param offset The start offset position in the children.
   * @param length The child count.
   * @param ordered True if content must be ordered.
   */
  public MixedContentModel(QName[] children, int[] type, int offset, int length, boolean ordered) {
    // Make our own copy now, which is exactly the right size
    fCount = length;
    fChildren = new QName[fCount];
    fChildrenType = new int[fCount];
    for (int i = 0; i < fCount; i++) {
      fChildren[i] = new QName(children[offset + i]);
      fChildrenType[i] = type[offset + i];
    }
    fOrdered = ordered;

  }

  //
  // ContentModelValidator methods
  //


  /**
   * Check that the specified content is valid according to this
   * content model. This method can also be called to do 'what if'
   * testing of content models just to see if they would be valid.
   * <p>
   * A value of -1 in the children array indicates a PCDATA node. All other
   * indexes will be positive and represent child elements. The count can be
   * zero, since some elements have the EMPTY content model and that must be
   * confirmed.
   *
   * @param children The children of this element.  Each integer is an index within the
   * <code>StringPool</code> of the child element name.  An index of -1 is used to indicate an
   * occurrence of non-whitespace character data.
   * @param offset Offset into the array where the children starts.
   * @param length The number of entries in the <code>children</code> array.
   * @return The value -1 if fully valid, else the 0 based index of the child that first failed. If
   * the value returned is equal to the number of children, then the specified children are valid
   * but additional content is required to reach a valid ending state.
   */
  public int validate(QName[] children, int offset, int length) {

    // must match order
    if (fOrdered) {
      int inIndex = 0;
      for (int outIndex = 0; outIndex < length; outIndex++) {

        // ignore mixed text
        final QName curChild = children[offset + outIndex];
        if (curChild.localpart == null) {
          continue;
        }

        // element must match
        int type = fChildrenType[inIndex];
        if (type == XMLContentSpec.CONTENTSPECNODE_LEAF) {
          if (fChildren[inIndex].rawname != children[offset + outIndex].rawname) {
            return outIndex;
          }
        } else if (type == XMLContentSpec.CONTENTSPECNODE_ANY) {
          String uri = fChildren[inIndex].uri;
          if (uri != null && uri != children[outIndex].uri) {
            return outIndex;
          }
        } else if (type == XMLContentSpec.CONTENTSPECNODE_ANY_LOCAL) {
          if (children[outIndex].uri != null) {
            return outIndex;
          }
        } else if (type == XMLContentSpec.CONTENTSPECNODE_ANY_OTHER) {
          if (fChildren[inIndex].uri == children[outIndex].uri) {
            return outIndex;
          }
        }

        // advance index
        inIndex++;
      }
    }

    // can appear in any order
    else {
      for (int outIndex = 0; outIndex < length; outIndex++) {
        // Get the current child out of the source index
        final QName curChild = children[offset + outIndex];

        // If its PCDATA, then we just accept that
        if (curChild.localpart == null) {
          continue;
        }

        // And try to find it in our list
        int inIndex = 0;
        for (; inIndex < fCount; inIndex++) {
          int type = fChildrenType[inIndex];
          if (type == XMLContentSpec.CONTENTSPECNODE_LEAF) {
            if (curChild.rawname == fChildren[inIndex].rawname) {
              break;
            }
          } else if (type == XMLContentSpec.CONTENTSPECNODE_ANY) {
            String uri = fChildren[inIndex].uri;
            if (uri == null || uri == children[outIndex].uri) {
              break;
            }
          } else if (type == XMLContentSpec.CONTENTSPECNODE_ANY_LOCAL) {
            if (children[outIndex].uri == null) {
              break;
            }
          } else if (type == XMLContentSpec.CONTENTSPECNODE_ANY_OTHER) {
            if (fChildren[inIndex].uri != children[outIndex].uri) {
              break;
            }
          }
          // REVISIT: What about checking for multiple ANY matches?
          //          The content model ambiguity *could* be checked
          //          by the caller before constructing the mixed
          //          content model.
        }

        // We did not find this one, so the validation failed
        if (inIndex == fCount) {
          return outIndex;
        }
      }
    }

    // Everything seems to be in order, so return success
    return -1;
  } // validate

} // class MixedContentModel
